Method of treating pectin



Patented Nov. 17, I936 fornia Fruit Growers Exchs l Ins Angeles, Calif.,a corporation of California No Drawing. J-Applieation April 10, 1934,-

- Serial No.71 9 ,893 a 1 '22 Claims. (01. 99-4132) This inventionrelates to a method of treating previously extracted, solid pectinwhereby certain fundamental and inherent characteristics of the pectinmay be changed.

5 Pectin is utilized commercially in-the manuiacture of variousproducts, and each trade requires that the pectin have certain uniformcharacteristics, although such requirements diifer for diflerent tradesand uses.

a pectin with an unvarying rapid setting rate is required for otheruses. Heretcfore it'has been difficult, if not impossible, for a pectinmanufacturer to manufacture pectin with a predeter-a 15 mined anduniform setting time or rate. Difierent source materials and extractionmethods pro duce pectins with differing and generally uncontrollablesetting characteristics.

fore a distinct need for some method whereby the setting time or settingrate of pectin can be controlled or modified.

This invention 'is based upon the disc overy that f it is possible toalter, at will, one of the inherent, intrinsic and fundamentalcharacteristics of pectin, namely, its setting time, or its inherentability to cause gelation to proceed in a Jelly batch at a certaindefinite rate. and means of this invention, the setting. time of anypreviously extracted pectin may be changed 30 in the desired direction.The'setting'time of a pectin, as used herein, refers to that interval oftime which elapses between the instant at which a jelly batch containingstandard proportions of sugar, acid, pectin and total solids is formedand 35 that at which gelation or Jellification into a coherent mass canbe observed. v

' Generally stated, the method comprises contacting the pectin with areagent adapted to materially alter the intrinsic setting time of said40 previously extracted pectin, and maintaining the reagent in contactwith the pectin for a time and at a temperature insumcient to destroythe gelation characteristics of the pectin or materially affect thetexture of the gel which may subse- 45 quentiy be formed from suchtreated pectin.

The treating reagent may be either liquid or gaseous, aqueous oranhydrous. The, preferred reagent is an acid, an acidic, or an acidforming substance. For convenience in handling and ap- 50 plication ofthe reagent, a liquid may be 'used as a carrier. The liquid mediumshould not-act as a solvent or dispersing medium for the solid pectinbeing treated, and preferably the medium or carrier should not interactchemically with the as acid used under the conditions prevailing dur-Certain uses require 1 10 a pectin with a uniformly slow setting rate,while There is, there- By the method ce1lulosic source material.

ing treatment. An acidified alcohol illustrates a desirable treatingagent. V

, An object of the invention, therefore, is to disclose and providesmethod ofaltering the setting a time of a previouslyextracted pectin, 5Another object is to disclose and provide a.

method of treating previously extracted pectin in various degrees ofpurity for the-purpose of altering, and particularly retarding, thesetting rate or time of the pectin. v 0

A further object is toprovide a method whereby it is possible to alterthe characteristic setting time of a pectin to any desired definite andpredetermined value.

Another object of the invention is to provide a method and means fortreating pectin with an acid reagent in the presence of a relativelynondispersing organic liquid for the purpose of retarding the settingrate or increasing the setting time of a previously extracted pectin. m

. Other objects and advantages of. the invention will appear more fullyand at large hereinafter.

It is to be understood that this invention is directed to the treatmentof pectin in solid form and particularly to the treatment of a pectinwhich has been previously extracted from a Various methods of,extraction arelmown and need not be described herein. In such previouslyknown methods, the

pectin is precipitated from the extracts with alcohol, by salting out orby the so-called aluminum precipitation process disclosed in patent No.1,497,884. a

It has been determined that the process of this invention is applicableto pectins extracted from any source, such as, for example, citrus peel,apple pomace, etc. Moreover, the process does not appear to beinfluenced by the method of extraction, precipitation or purificationused prior to the application of the process of this in- 0 vention. Thesolid, preferably finely divided, pectincapable of being treated inaccordance with this invention may be either of a technical grade or ofa more extensively purified grade. It may contain appreciable quantitiesof water or it may be substantially dry.

As has been stated hereinbefore, the method of the inventioncontemplates contact of a previously extracted solid pectin with atreating agent adapted to materially alter the intrinsic setting time 01the pectin. The preferred process is carried out by contactingthe'pectin with an acidified liquid medium. In order to illustrate theprocess and results attained thereby, the following examples are given.In each of the foll5 tacted with 100 ml. of organic liquid to whichthere was added ml. or 10 normal hydrochloric acid. The pectin wasmaintained in contact with the treating agent for a period of 24 hoursat a temperature of 25 C. The pectin betore treatment was found to setto a jelly under standard conditions of sugar and acidin 100 seconds(1.66 minute). The efiect or various treating liquids upon the settingtime of the pectin under these conditions were observed to be asfollows:

Liquid medium used Time oi set yd 3818 time.

It is-to be remembered that in each instance 10 ml. of 10 N.hydrochloric acid was added to 100 ml. of the organic medium. Thepercentages [following the name of the liquid used are approximate forthe concentration of the liquid before adding acid and pectin.

Dilution of the organic liquid used as a carrier for the acid influencesthe rapidity with which the setting timeof the pectin is altered withina given contacting period. -'I'he effect of various ethyl alcoholwatermixtures (containing HCL in the same proportions as that givenhereinabove) on the setting time of the pectin is shown in the followingtable:

In the above te'st,- 10 ml. of 10 N. hydrochloric acid was added to theliquid and grams of pectin brought into contact therewith and maintainedin such contact for a period of about 43 hours. at about C. The dilutionof the ethyl alcohol retards the set more energetically.

Absolute methyl alcohol when used as a carrier for the acid appears toaccelerate the set instead of retarding the setting time. Upon dilution,methyl alcohol-acid mixtures retard or prolong the setting time. Whenacetone is diluted, on the other hand, it appears to lose some 'of itsgreat ability to allow retardation of the setting time by. the acidcarried thereby. Although 100% acetone prolongs the setting time to 28minutes when pectin having an original setting time of 1.66 minutes istreated with a mixture consisting of 100 ml. of acetone and 10 ml. of 10N. hydrochloric acid for 12 hours at 25 C., a set of only 8 minutes isobtained when the treating liquid consists of 75 ml. acetone, 25 ml.water and 10ml. of 10 N. hydrochloric acid. I

Attention is called to the fact that after the setting rate of a pectinhas been retarded by treatment with acid as here described, the settingrate can subsequently be accelerated (setting time shortened) bytreatment with acid in the presence of methyl alcohol. The setting timeof a pectin can thus be repeatedly altered, as desired. 1

The treating agent should contain an acid or acidic component. Whenorganic liquids are used as media for theacidic components, any of themineral acids may be used whenever the organic liquid is a solventtherefor. Although sulfuric, sulfurous phosphoric and nitric acids aresuitable, hydrochloric acid isthe preferred acid. Organic acids such aslactic may also be used. When pectin is contacted with an aqueous acidsolutionin accordance with this invention, its setting time is altered(generally lengthened or prolonged) but due to imbibition of water, thepectin is more .difficultly handled. As an illustration, when pectin isallowed to remain in contact with 85% lactic acid, a plastic mass isobtained which has to be hardened in 90% alcohol and ground.

The reagent used in obtaining the desired alteration in setting time ofpectin may be anhydrous. The treating agent may comprise. an acidicsubstance, such as chlorine, hydrogen suifide, sulfur dioxide or sulfurtrioxide. Pectin concontacted with any of these acidic gases and analteration in setting time obtained. Dry hy- It appears that any acid oracid radical may be employed, provided it is of sufiicient activity andhas no destructive action upon any of the constituents of the mixture.The more active acids uniformly produce retardation of the set in ashorter treating time than less active acids. The concentration'of theacid used may also vary over a very wide range, for example, from 0.5%to as high as 25% HCl, the concentration.

of acid used being influenced by time and temperature conditions whichit is desired to use. The higher the concentration of the acid, theshorter the treating time. With solutions containing high concentrationsof acid, a treating time of only a few minutes may be sufilcient.

The use of very high concentrations of acid is not recommended, however,as some degradation of the pectin and a loss in jelly strength or jellyunits may result.

The preferred organic liquids used as media contain the methyl radical,the acetyl radical or a saturated alkyl group., Specific examples of'such liquids are methyl alcohol, ethyl alcohol, normal propyl alcohol,isopropyl alcohol, normal butyl alcohol, isobutyl alcohol, secondarybutyl alcohol, tertiary butyl alcohol, amyl alcohol, isoamyl alcohol,ethyl ether, acetone, methyl ethyl ketone, acetyl chloride, ethylacetate, acid methyl sulfate, etc.

Among other liquids which may be used are aliphatic and aromatichydrocarbons and their derivatives, the preferred liquids being thesimpler aliphatic hydrocarbon derivatives such as alcohols, ketones,aldehydes, amines and ethers and the aromatics of low molecular weight,such as benzol. Air and gases or vapors which do not chemically reactwith the treating reagent to any substantial or detrimental degree areliquid mediashould not exert any appreciable solvent or dispersingeffect upon the solid pectin 2B taining about 8% to 10% of moisture maybe handling mixtures of liquid withsolid pectin,

:when the pectin swells excessively. Although the organiciiquids (whenmiscible with water, as diethylene glycol, for example) may be dilutedwith water, the relative proportion of water should not be increased tosuch a point that any excessive hydration and/or agglutination of thepectin particles takes place. Although dilution of ethyl alcohol appearsto increase the rate at which the setting time 01' the pectin isretarded, it is not ordinarily desirable to reducethe proportion ofethyl alcohol below about 45% of the total liquid, as further dilutiongives rise to mechanical dithculties incident to the swelling andhydration of the pectin particles.

The conditions of temperature, time and acid concentration sheet therapidity or the extent to which the setting time of the pectin isaltered. when higher temperatures are used, the time of contact may beshortened or a solution of lower acid concentration may be used toproduce a desired effect. The fineness of division of the solid pectinbeing treated plays but a secondary part. It is not necessary that thesolid pectin be finely divided. Relatively coarse pectin in the form offlakes or in the fibrous condition which it assumes upon precipitationwith alcohol, may be treated just as eflectively as a solid pectindisintegrated suillciently to pass through a 60 mesh screen. whentreating solutions ofhigher acid concentration are used, better resultsare obtained by having the pectin in a finely divided condition sons topass through a 40, 80 or 100 mesh.

.As a result 'of some processes of extracting pectin, the pectinparticle'scontain residual acid. Usually the pectin is washed repeatedlywith alcohol' or other solvent in which'the pectin is difflcultlysoluble or insoluble (such as asolution of a salt of a strong base and aweak acid) in order to controllably reduce the acid and other possibleimpurities. In accordance with-this inventionfihowever, theacid-containing pectin resulting from such processes may be stored foran appreciable-time in a substantially dry condition (from about 2% to10% mo) or with the addition of but enough moisture to dampen thepectin, and thereby permit the setting time of the pectin to be alteredor prolonged.

After a previously extracted solid pectin has been treated in the mannerdescribed hereinabove, it may be washed or rinsed with fresh or neutralalcohol or other suitable solvent, and

55 then dried. The solvent used maycontain a bufier salt, such as sodiumcitrate or sodium carbonate, or an alkali. The removal of residualacidity stabilizes the pectin and stops further alteration insetting-time. After washing, the pectin may be dried in any suitablemanner and if necessary reduced to the' desired state of division.Whenever the ultimate use of the pectin is facilitated thereby, thepectin may be standardized as to jelly grade or admixed with suitablequantities of acid or acid-forming materials, additional buffer salts,sugar, and similar materials.

It will be evident from the description given hereinabove that a processhas been disclosed which permits the manufacturer, dealer or user ofpectin to alter at will the setting time of this substance. Although asstated hereinabove, the primary object attained by the method is thealteration in setting or gelation time of the pectin, other advantageousresults are obtained at the same time. Even though some mechanicallosses may be encountered in the practice of the'method, for example, animprovement in the actual grade of the pectin isobtained when theprocess is ca'rriedout under optimum conditions, sothat the jelly unityield is over 100%. The pectin treated in accordance with this inventionis generally lighter in color than the original solid pectin, has a-'lower ash content,

and there is some indication that the treated pectin is ground morereadily than the pectin not so treated.

Although specific materials have been mentioned hereinabove as suitablereagents for use in the process of this invention, they have been setforth for purposes of illustration only and the invention is not limitedthereto. All changes. modifications and equipments coming within thescopeof the. appended claims are embraced thereby. g i I claim: 1. Amethod of treating pectin which comprises contacting solid. previouslyextracted pectin in the form of discrete particles with, an acidicreagent adapted to materially alter the intrinsic setting time of thepectin, the pectin being maintained in contact with the reagent for aperiod of time and at a temperature insufli-- cient to destroy thegelation characteristics of the pectin but suflicient to materiallyalter the intrinsic setting time hereof.

2. A method as defined in claim 1, in which the reagent comprises anon-dispersing liquid medium incapable of dissolving the pectin to anyappreciable extent, and an acid.

3. A method as defined in claim 1, in which the reagent comprises anacid.

4. A- method of treating pectin as defined in claim 1, in which thereagent is an acidic gas from the group consisting of hydrogen chloride,chlorine, hydrogen sulfide, sulfur dioxide and sulfur trioxide.

5. A method of treating pectin as defined in claim 1, in which thereagent comprises an oran acid.

9. A method of treating pectin as defined in claim 1, in which thereagent comprises an organic liquid containing the acetyl radical, andan-acid.

10. A method of treating pectin as defined in claim 1, in which thereagent comprises an organic liquid from the group consisting of thealcohols, ketones, aldehydes, glycols and benzol containing the methylradical, the acetyl radical,

or a saturated alkyl group, and an acid.

11. A method of treating pectin as defined inclaim 1, in which thereagent is maintained-in substantial contact with the pectin for aperiod of time of from 1 to 48 hours.

12. A method as defined in claim 1, in which the reagent comprises anon-dispersing liquid medium incapable of dissolving the pectin to anyappreciable extent, and an acid, the reagent' 1 ten the surfaces of thepectin particles.

13. A method of treating pectin whereby the setting time thereof isaltered, which comprises contacting previously extracted solid pectin inthe form of discrete particles with a carrier having substantially nosolvent or dispersing action on the pectin, said carrier containing anacid radical, and maintaining the carrier and its acid radical incontact with the pectin for a time sufficient to materially alter thesetting time of the pectin.

14. A method as defined in claim 13 in which the pectin is washed aftercontact to diminish residual acidity thereof.

15. A method of treating pectin whereby the setting time thereof isaltered, comprising contactin'g solid pectin with an acidic reagent andmaintaining such contact for a time sufilcient to materially alter thesetting time of the pectin but insufficient to destroy the gelatincharacteristics of the pectin, then separating the pectin from theacidic reagent, and washing the pectin to diminish residual aciditythereof. 16. A method of treating pectin as defined in claim 1 in, whichthe reagent comprises an organic liquid containing a saturated alkylgroup, and an acid. 17. A method of treating a previously extractedsolid pectin which comprises contacting ganic liquid incapable ofdissolving the pectin to any appreciable extent.

20. A method of treating pectin as defined in claim 1 in which thereagent comprises a water miscible organic liquid incapable ofdissolving the pectin to any appreciable extent.

21. A method of treating pectin as defined in claim 1 in which thereagent comprises a Water.

miscible organic liquid incapable of dissolving the pectin to anyappreciable extent, and an acid.

22. A method of treating pectin as defined in claim 1 inwhich thereagent comprises an organic liquid incapable of dissolving the pectinto any appreciable extent, and an acid.

GLENN H. JOSEPH.

' CERTIFICATE OF CORRECTION.

Patent No. 2,061 158.

the above numbered patent requiring 0 col claim 11 she November 17,1936.

. GLENN H. JOSEPH.

It is hereby certified that error umn,

I Page 2, first page 3, second column, line '71,

uld be read with these corrections therein that the same may conform therecord of the case in the Patent Office.

(Seal) Henry Van Arsdale Acting Commissioner of Patents.

appears in the printed specification of orrection as follows: line 3,for the word "or" read of;

, after "from" insert about; and that the said Letters Patent 1 ten thesurfaces of the pectin particles.

13. A method of treating pectin whereby the setting time thereof isaltered, which comprises contacting previously extracted solid pectin inthe form of discrete particles with a carrier having substantially nosolvent or dispersing action on the pectin, said carrier containing anacid radical, and maintaining the carrier and its acid radical incontact with the pectin for a time sufficient to materially alter thesetting time of the pectin.

14. A method as defined in claim 13 in which the pectin is washed aftercontact to diminish residual acidity thereof.

15. A method of treating pectin whereby the setting time thereof isaltered, comprising contactin'g solid pectin with an acidic reagent andmaintaining such contact for a time sufilcient to materially alter thesetting time of the pectin but insufficient to destroy the gelatincharacteristics of the pectin, then separating the pectin from theacidic reagent, and washing the pectin to diminish residual aciditythereof. 16. A method of treating pectin as defined in claim 1 in, whichthe reagent comprises an organic liquid containing a saturated alkylgroup, and an acid. 17. A method of treating a previously extractedsolid pectin which comprises contacting ganic liquid incapable ofdissolving the pectin to any appreciable extent.

20. A method of treating pectin as defined in claim 1 in which thereagent comprises a water miscible organic liquid incapable ofdissolving the pectin to any appreciable extent.

21. A method of treating pectin as defined in claim 1 in which thereagent comprises a Water.

miscible organic liquid incapable of dissolving the pectin to anyappreciable extent, and an acid.

22. A method of treating pectin as defined in claim 1 inwhich thereagent comprises an organic liquid incapable of dissolving the pectinto any appreciable extent, and an acid.

GLENN H. JOSEPH.

' CERTIFICATE OF CORRECTION.

Patent No. 2,061 158.

the above numbered patent requiring 0 col claim 11 she November 17,1936.

. GLENN H. JOSEPH.

It is hereby certified that error umn,

I Page 2, first page 3, second column, line '71,

uld be read with these corrections therein that the same may conform therecord of the case in the Patent Office.

(Seal) Henry Van Arsdale Acting Commissioner of Patents.

appears in the printed specification of orrection as follows: line 3,for the word "or" read of;

, after "from" insert about; and that the said Letters Patent

